This invention relates to a self-contained, electrically fired rotary actuator for use in vehicles and in other applications where a high speed and powered rotational force moving through a predetermined angle is required to operate a latch or position a protective restraint or exit panel for safety of persons.
Tests conducted by the Federal Government and by industry have demonstrated that the application of a restraint upon a passenger involved in a vehicle accident must be within a fraction of a second after impact to provide useful protection. In case of accidents involving vehicles carrying a large number of passengers, such as aircraft or buses, emergency exits must be opened within seconds. Maximum public acceptance and use of restraint systems and vehicle emergency devices requires the employment of unobtrusive devices which permit an optimum freedom of movement by passengers in normal vehicle operations, yet instantaneous protection when an accident occurs. A high speed device applying a predetermined amount of linear or rotary force is required in emergencies to open or close latches or turn protective devices, exists and other devices to a desired position. The energy source for these emergency linear or rotary force devices may be centralized or may be unitized with the device itself for reliability or economies in space or weight. Actuation by springs, compressed gases or fluids under high pressure is well known in prior art. Explosive actuators are also well known.
Review of prior art shows wide usage of compressed gas cylinders or cartridges to inflate air bag protective devices in vehicles and the use of electrically fired detonators to rupture the diaphragm sealing the gas cylinder. U.S. Pat. No. 3,567,245 granted to G. A. Ekstrom on Mar. 2, 1971, discloses a diaphragm made of friable material sealing a compressed gas cylinder, such diaphragm being shattered by an explosive charge upon electrical impulse, thereby releasing the gas into an air bag contained within the vehicle dashboard. In U.S. Pat. No. 3,777,772 issued on Dec. 11, 1973, to T. E. Arnold et al, a domed diaphragm having a discontinuous groove and a shaped charge with electrical leads is inserted into the outlet end of a compressed gas cylinder and on detonation the domed diaphragm is severed by the shaped charge along the discontinuous groove, thereby releasing the gas into a manifold and from the manifold to an inflatable cushion.
Movement of a vehicle passenger restraint from a stored position to a desired protective position has been previously achieved by the use of springs, cables, air bag configuration or a combination of these. U.S. Pat. No. 3,664,682 granted to C. E. Wycech on May 23, 1972, shows the rotation of a cushion and separate air bag into position by release of compression springs. U.S. Pat. No. 3,753,576 issued on Aug. 21, 1973 to J. F. Gorman, teaches the positioning of a composite elliptical bag over a passenger by gas and spring ejection followed by inflation of the shaped bag. U.S. Pat. No. 3,774,936 granted to R. R. Barnett et al on Nov. 27, 1973, shows an inflatable cushion guided into position by, the use of endless loop cables anchored at one point on each side of the cushion, and U.S. Pat. No. 3,836,168 issued to K. Honaka on Sept. 17, 1974 teaches the drawing of a protective net into position by projecting inflatable tubes or projectiles attached to side cables or cords which are drawn tight by expansion of separate inflatable tubes or projectiles.
It is the primary purpose of this invention to provide a compact high seed rotary actuator which uses the force from high pressure gases released from a cylinder to drive a piston which rotates a shaft with attached gear, pulley, arm or panel, thereby moving a latch, tightening a strap or positioning a protective panel or air bag for greater passenger safety. It is a further purpose to provide such a device capable of sequentially unlatching and turning a shaft with attachments to a desired position. Another objective is to provide such a device which sequentially rotates a shaft with attachments to a desired position and then releases the high pressure gas into a surrounding tube or hollow shaft connected to one or more air bags or telescoping tubes with attached plates or straps. A still further objective is to provide such a device which permits independent positioning of protective restraints or air bag containers during normal operation of a vehicle but moves automatically into desired position for passenger protection in the event of accident.
Other objects and advantages of the invention will be apparent from the following description.